Frank, All F.D.'s did not have Chief Drivers. SF and other large cities had drivers for Battallion Chiefs. They were located in fire houses in different sections of town. All individual firehouses did not have Batt. Chiefs. It was policy for BC's to have drivers primarily for communication. In the early days there were no radio/telephones. Even today the block fire alarm boxes could be used for Morse code communication. All drivers were supposed to be versed in this and other areas. In later years with advanced communication systems this Morse code system was very seldom used. That is my take.